Spicule seismology:
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Principal Investigator: R. Erdelyi (Sheffield)
Co-Investigators: J.G. Doyle (Armagh Observatory), M.D. Marjarska (Armagh
Observatory), M. Mathioudakis (QUB), D. Jess (QUB), R. Morton (Sheffield) &
K. Reardon (QUB). E. Scullion (Armagh Observatory)
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Main point-of-contact:
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Gerry Doyle jgd@arm.ac.uk with copies to
Maria Madjarska madj@arm.ac.uk
Robertus von Fay-Siebenburgen robertus@sheffield.ac.uk
Mihalis Mathioudakis M.Mathioudakis@qub.ac.uk
Requested Observing interval
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We request 4 shifts; 28, 29, 30 April & 1 May from 15:00 UT for ~4 hrs.
SUMER has allocated for this 28th & 29th April from 14:00 UT - 18:00 UT.
Pointing
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Two days at the limb and two days in an AR.
Introduction
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The rapid rise of plasma temperature up to 1 MK from the solar photosphere
towards the corona is still an unresolved problem in solar physics. It is
clear that the mechanical energy of sub-photospheric motions is transported
somehow into the upper solar atmosphere, where it may be dissipated leading
to the heating of the ambient plasma. A possible scenario of energy
transport is that the convective motions and solar global oscillations may
excite magnetohydrodynamic (MHD) waves in the photosphere, which may then
propagate through the chromosphere carrying relevant energy into the
corona.
Spicules are grass-like spiky features best seen in chromospheric spectral
lines at the solar limb. Beside the morphological and global dynamic
studies there are early observational reports on oscillatory phenomena in
spicules. However, only a limited number of studies have addressed spicule
oscillations with recent high-resolution ground and space-based
observations. It is strongly anticipated that signatures of the energy
transport by MHD waves through the chromosphere may be detectable in the
oscillatory dynamics of spicules. A comprehensive novel observational study
of waves and oscillations in spicules, to the best of our knowledge, is
still lacking and such observational campaign could clarify important
details of the magnetic coupling from the photosphere to corona.
We plan to use existing Hinode, SoHO & TRACE sequences, in addition to
acquiring high-cadence ROSA & IBIS data (weather permitting). What is the
relationship between spicules, macrospicules and Jets as seen in the TR and
corona? Why are spicules as seen in ARs of shorter duration? Does this
imply a different heating mechanism? How do spicules manifest themselves in
the TR and corona?
Primary Objectives
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The primary objective of this proposal is not only to study the dynamic
activity in the lower solar atmosphere but to trace that activity to the TR
and corona.
Our observing setup will allow us to identify oscillatory power (via FWHM
oscillations) in velocity and intensity with frequencies in excess of
20mHz. With XRT and EIS, we will acquire images and spectral data to
enable a determination of the flow, temperatures and electron density
structure in the upper atmosphere. SOT will provide magnetograms in Na D
I, Ca II K and if possible H alpha line center and wing emission.
TRACE will provide high-cadence observations with the 171 A filter.
SUMER will provide high spectral resolution for selected transition region
lines providing a diagnostic of the flow structure.
Instruments
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SUMER
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INN_SS_NV_S2 - QS
INN_SS_NV_S5 - AR
Participating instruments and observatories
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Hinode
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SOT (BFI):
FILTERS: Ca II H
FOV: 120"x100"
CADENCE: As high cadence as possible.
START TIME: 15:00 UT
END TIME: TBD
REPETITION: Repeat to fill the available time slot
XCEN TBD
YCEN TBD
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
TARGET: Polar region (backup target Active region)
SOT (NFI):
FILTERS: Na I D shuttered IV plus Halpha center and wing(s) if possible
FOV: 220"x164"
CADENCE: As high cadence as possible.
START TIME: 15:00
END TIME: TBD
DURATION: 3-4 hrs
XCEN: around 300 "
YCEN: around 100"
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
TARGET: Polar region (backup target Active region)
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EIS:
STUDY: madj_qs (backup study - madj_ar)
STUDY DURATION: around 32 min
REPETITION: run once
FOV: 70"X248"
START TIME: 15:00 UT
END TIME: TBD
XCEN: TBD
YCEN: TBD
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
TARGET: Polar region (backup target Active region)
STUDY: madj_qs_small (backup study - madj_ar_small)
STUDY DURATION: around 12 min
REPETITION: repeat to fill the remaining time slot
START TIME: TBD
END TIME: TBD
FOV: 24"x248"
XCEN: TBD
YCEN: TBD
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
TARGET: Polar region (backup target Active region)
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XRT:
FILTERS: Al/Poly, several G-band images for coalignment
CADENCE: ~40 s
FOV: 384"x384"
START TIME: 15:00
END TIME: TBD
XCEN xcen = xcen(SOT)
YCEN ycen = ycen(SOT)
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
TARGET: Polar region (backup target Active region)
**********************************************************************
**********************************************************************
TRACE:
171 A filter with 1550, 1700, 1600 context images every 30 min.
Rot. comp.: Rotation compensation to be applied i.e. feature tracking
START TIME: 15:00
END TIME: TBD
Target: Polar region (backup target Active region)
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Sac Peak .. Dunn Solar Telescope
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ROSA & IBIS
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With the DST equipped with ROSA & IBIS we aim to achieve the following:
(a) Full Stokes polarimetry using the magnetically sensitive Fe I line at
6302.5A.
(b) Scan individual line profiles. Each scan will last for approximately 3 sec
and waves with frequencies up to ~160 mHz will be studied (Nyquist frequency).
Lines that may be used include Fe I (7090A) & Ca II (8542A) that are formed in
the low photosphere, upper photosphere and chromosphere respectively.
(c) The IBIS observations will be combined with simultaneous ROSA imaging in
H alpha, G-band, Ca II k and white light continuum. ROSA imaging at high
spatial and temporal resolution will be essential as it will allow us to
disentangle any intensity oscillations that may be associated with kink and/or
sausage waves modes. We will therefore be in a position to show the unambiguous
detection of Alfvenic wave modes that may exist in the lower solar atmosphere.